Play the latest strategy and tower defense WebGL and html5 games online on brightestgames.com. Try the best strategy and defense galaxy and alien games and train your brain in the best defense strategies online! Click to play now this fun html5 game called The Lost Planet Tower Defense games. The Lost Planet Tower Defense is an excellent strategy in which you have a total of ten differently challenging levels. In each round, your mission is to help a cosmonaut who has failed on an unknown planet to defend his base from monster and monster attacks. Deploy along the defense tower path, dispose of passing creatures and collect crystals for income.